• BMB Reports
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• 제46권6호
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• pp.328-333
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• 2013

Many bioactive molecules like recombinant human bone morphogenetic protein 2 (rhBMP-2) have been developed for mineralized bone grafts, for which proper scaffolds are necessary to successfully apply the bioactive molecules. In this study, we tested the osteogenic efficacy of rhBMP-2 produced in-house in combination with gelatin sponge as the scaffold carrier in a rabbit radial defect model. The efficacy of the rhBMP-2 was determined by alkaline phosphatase activity assay of C2C12 cells. Two groups of ten rabbits each were treated with rhBMP-2/gelatin sponge, or gelatin sponge only. At 4 weeks, rhBMP-2/gelatin sponge grafts showed more bone regeneration than gelatin sponge grafts, as determined by X-ray radiography, micro-computed tomography, and histological analyses. At 8 weeks, rhBMP-2/gelatin sponge grafts exerted much stronger osteogenic effects. The study demonstrates the improved osteogenic efficacy of the rhBMP-2/gelatin sponge grafts in a rabbit radial bone defect model acting as a bone-inductive material.

• Journal of Periodontal and Implant Science
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• 제39권1호
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• pp.77-86
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• 2009

Purpose: Recombinant human bone morphogenetic protein-2(rhBMP-2) has been evaluated as potential candidates for periodontal and bone regenerative therapy. In spite of good prospects in BMP applications, there is economically unavailable for clinical use in dental area. The purpose of this study was to evaluate the osteogenic effect of rhBMP-2 produced by E.coli expression system. Materials and methods: Eight-mm critical-size calvarial defects were created in 48 male Sprague-Dawley rats. The animals were divided into 6 groups of 8 animals each. Each group received one of the following: Negative control(sham-surgery control), positive control(absorbable collagen sponge(ACS) alone) and experimental(ACS loaded with rhBMP-2). Defects were evaluated by histologic and histometric parameters following 2- and 8-week healing intervals. Results: The experimental group showed significant defect closure at 2 and 8weeks than the sham surgery and positive control groups. Moreover, the experimental group showed significantly greater new bone and augmented area than the other groups at both 2 and 8weeks. Conclusion: rhBMP-2 produced by E.coli expression system may be effective for bone regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권4호
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• pp.317-326
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• 2006

Purpose : The aim of this study was to evaluate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) injected on the rate of new-bone formation for distraction osteogenesis on dogs. Materials & Methods : Twelve adult dogs were randomly selected into two groups of six dogs on each. Unilateral osteotomies were performed on the body of the mandible and an intraoral distractor was mounted to the mandible on dogs. One group was treated with injection of rhBMP-7 and the other group served as the control. RhBMP-7 was administered on the day of surgery by single injection into the medullary bone at the osteotomy gap. Distraction was performed five days after osteotomy as a rate of 0.5 mm twice per day for 10 days. The animals were then sacrificed at 2, 4, and 8 weeks after completion of the distraction. Two dogs in each group, totaling four dogs, were killed at 2 weeks, 4 weeks, and 8 weeks after completion of distraction, respectively. The lengthened mandibles were harvested and processed for radiographic and histological examinations. In addition, immunohistochemical examination using osteocalcin expression was studied. Results : Radiographs showed accelerated regenerate ossification with maturation of new bone in the rhBMP-7 group comparing with the control group at the 4 weeks of the consolidation. There was no significant difference in the radiographic findings at the 2 weeks and 8 weeks of the consolidation period. Histological findings demonstrated increased bone healing pattern in the rhBMP-7-treated group during all observation period. The expression of osteocalcin immunoreactivity was hardly detected in the normal mandible of dog, but the expression was detected in all experimental rhBMP-7 treated specimens. There were also significant increasing in number of positive immunostaining cells and staining intensity of osteocalcin expression in the rhBMP-7 treated group compared with those of the control group on 2-weeks and 4-weeks. There was a significant decreasing in staining intenstiy of all both two groups on 8 weeks of consolidation period, but significant differences of immunostaining was not seen in two groups. Conclusions : A single injection of rhBMP-7 at the time of osteotomy may stimulate the rate of regenerate ossification and increase callus maturation during distraction osteogenesis. In addition, it may shorten the distraction osteogenesis procedure and decrease the prevalence of complications associated with mandibular distraction osteogenesis.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권6호
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• pp.353-359
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• 2013

Purpose: Extensive research is actively ongoing for development of an ideal bone substitute that meets the gold standard. Tooth was selected as a donor site for evaluation of potentials in bone substitutes based on its similar chemical compositions to alveolar bone. Previous studies have evaluated inorganic components of autogenous tooth bone graft material (AutoBT) and osteoconductivity. In continuation from the previous studies, the current study was conducted for analysis of organic components and evaluation of osteoinductivity of AutoBT. Methods: Forty-six extracted teeth were collected from actual patients (Korea Tooth Bank, R&D Institute). Extracted teeth were processed into AutoBT and implanted in dorsal subcutaneous muscular tissues of 15 athymic mice. Biopsy samples were harvested at two, five, and eight weeks. The Bradford assay, sodium dodecyl sulphate polyacrylamide gradient gel, and western blotting were performed for investigation of organic contents of AutoBT. Results: Histology analyses showed signs of new bone formation as early as two weeks. Results of the Bradford assay indicated the existence of noncollagenous proteins (NCP). 0.29% (2.89 mg/g) of proteins were extracted by weight in the root portion of AutoBT; 0.02% (0.029 mg/g) and 1.79% (17.93 mg/g) of proteins were measured by weight in crown and block-form of AutoBT, respectively. However, recombinant human bone morphogenetic protein-2 was not observed in AutoBT. Conclusion: Within the limitation of the current study, AutoBT induced new bone formation by NCP embedded in dentin.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권4호
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• pp.419-427
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• 2008

The present study aimed to investigate the osteogenic potentials of differentiated osteoblast-like cells (DOCs) induced from bone marrow-derived mesenchymal stem cells (MSCs) on ${\beta}-tricalcium$ phosphate (${\beta}-TCP$) with recombinant human bone morphogenetic protein (rhBMP-2) in vitro. Osteoblast differentiation was induced in confluent cultures by adding 100 nM dexamethasone, 10 mM ${\beta}$-glycerophosphate, 50 mM L-ascorbic acid. The Alizarin red S staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were perfomed to examine the mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), receptor activator for nuclear factor ${\kappa}B$ ligand (RANKL), runt-related transcription factor 2 (RUNX2), collagen-Ⅰ (COL-Ⅰ). There were no significant differences in the osteogenic potentials of DOCs induced from MSCs on ${\beta}-TCP(+/-)$. According to the incubation period, there were significant increasing of Alizadin red S staining in the induction 3 weeks. The mRNA expression of ALP, RUNX2, and RANKL were higher in DOCs/${\beta}-TCP(-)$ than DOCs/${\beta}-TCP(+)$. According to rhBMP-2 concentrations, the mRNA expression of BSP was significantly increased in DOCs/${\beta}-TCP(+)$ compared to that of DOCs/${\beta}-TCP(-)$ on rhBMP 10 ng/ml. Our study presented the ${\beta}-TCP$ will have the possibility that calcium phosphate directly affect the osteoblastic differentiation of the bone marrowderived MSCs.

• 대한치과보철학회지
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• 제51권2호
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• pp.82-89
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• 2013

연구 목적: 본 연구는 양극산화 임플란트에 골형성단백질과 혈관내피세포성장인자를 코팅한 임플란트를 토끼의 경골에 식립하여 골과 임플란트 계면의 골유착 향상의 가능성을 평가하고자 시행하였다. 연구 재료 및 방법: 6마리의 토끼 양측 경골에 코팅을 하지 않은 양극 산화 임플란트(대조군)와 골형성단백질과 혈관내피세포성장인자를 코팅한 임플란트(실험군)을 각각 한쪽에 2개씩 식립하였다, 토끼는 2주, 8주에 각각 3마리씩 희생하였고 전체 식립된 임플란트는 24개이었다. 각 시기별, 그룹별 임플란트 수는 각각 6개씩이었다. 임플란트안정지수(resonance frequency analysis (RFA)), 회전 제거력(Removable torque measurement (RTQ))을 희생 시기에 측정하였다. 독립표본 t-test (SPSS Ver. 15.0, Chicago, USA)을 이용하여 2주, 8주에서 대조군과 실험군의 차이를 비교 분석하고, 유의수준95%에서 통계적으로 검정하였다. 결과:대조군과 실험군 모두 8주에서 우수한 골유착을 보였다. 특히 실험군에서 8주에 ISQ, RTQ 값 모두 대조군과 비교하여 우수한 값을 나타내었다 (P<.05). 하지만 2주에서는 두군 사이에 통계적 유의성을 보이지 않았다(P>.05). 결론: 골형성 단백질과 혈관내피세포성장인자를 임플란트 표면에 코팅하여 식립하는 것은 치유의 후반기에 골유착을 증대하는 것으로 사료된다.

• 대한치과보철학회지
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• 제49권3호
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• pp.254-262
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• 2011

연구 목적: 기존의 기계절삭 가공된 티타늄 표면에 생체활성 유기물질이 코팅된 생체 활성 임플란트에 관한연구가 최근에 많이 이루어지고 있다. 이러한 생체 활성 임플란트는 임플란트 자체에 골치유 및 골형성 효과를 부여할 수 있다. 본 연구의 목적은 생체 활성 임플란트 표면에 대한 연구 동향을 분석함으로써, 표면처리 기술 개발의 현황과 향후 발전 전망에 대해서 알아보고자 하였다. 연구 재료 및 방법: 본 문헌 분석 연구는 'Web of Science (http://isiknowledge.com, Thomson Scientific)'를 통해 SCI (science citation index) 등재 논문들을 기반으로 분석하였다. 주제별로 연구비중을 비교하기 위해서, 임플란트 표면 코팅에 사용되는 생체활성 유기물들로 키워드를 선정하고 각 키워드로 대표되는 리서치 그룹을 선정하여 각 그룹들의 연구 동향을 분석하였다. 또한 키워드별로 동물실험 동향을 분석하여 상용화 가능성에 대해서도 고찰하였다. 결과: 연구의 비중은 콜라겐, 피브로넥틴, 골형성단백질, RGD (Arg-Gly-Asp) 순으로 나타났으며, 콜라겐을 이용한 연구가 40%로 가장 많은 연구가 이루어지고 있었다. 네가지 주제 모두 시간의 경과에 따라 연구횟수가 증가하는 양상을 보였으며, 특히 RGD에 관한 연구횟수가 가장 급격하게 증가하였다. 콜라겐 대표 리서치 그룹의 연구 동향을 분석하였을 때, 콜라겐은 단독 사용보다는 다른 생체활성 유기물 및 무기물과의 병용 처치에 관해 주로 연구가 되고 있었으며, 특히 세포외기질인 콘드로이틴 설패이트와의 병용 처치에 관한 연구가 가장 많이 이루어지고 있는 것으로 나타났다. 골형성단백질의 대표 리서치 그룹들에서는 rhBMP-2 (recombinant human bone morphogenetic protein-2)에 관한 연구가 주로 이루어지고 있었다. 동물실험에 관한 연구 동향 분석 결과 콜라겐은 차폐막 혹은 약물 전달 매체로서 주로 사용되고 있었고, 골형성단백질은 치조골이식술 혹은 임플란트 표면 코팅에 대한 효과가 연구되고 있었다. 결론: 연구 결과를 주제별로 분석하였을 때 주제별로 일관성 있는 결과를 얻기 어려웠으며, 보다 나은 결과를 얻기 위한 기계적 표면처리와 여러 세포외기질, 성장인자 등의 생체물질의 최상의 조합을 찾기 위한 노력이 진행중이었다. 연구가 초기단계에 머물고 있기 때문에 상용화에 이르기까지는 많은 시간과 노력이 필요할 것이다.

• 대한치과보철학회지
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• 제48권3호
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• pp.202-208
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• 2010

연구 목적: 이 연구의 목적은 골형성단백질 (recombinant human Bone Morphogenetic Protein-2; rhBMP-2)이 코팅된 임플란트가 치조골 증대에 미치는 영향을 알아보는 것이다. 연구 재료 및 방법: 6마리의 비글견이 실험에 사용되었다. 6개의 8 mm 길이의 임플란트가 발치 후 6개월 이상의 충분한 치유기간이 경과한 비글견의 치조골에 5 mm 깊이로 식립되었다. 각각의 동물에 좌측과 우측의 악궁-분할형으로 임의추출하여 한쪽에는 1.5 ml/mg 농도의 rhBMP-2가 코팅된 임플란트를, 반대편에는 코팅되지 않은 대조군 임플란트를 식립하고 임플란트 주변 골에 round bur를 이용하여 피질골 천공을 시행하였다. 점막골막판막에 이완절개를 시행하여 판막을 접합시키고 봉합하여 임플란트가 피개되도록 하였다. 방사선 사진 촬영은 수술 직후 (기준치), 수술 4주후, 수술 8주 후에 시행하였다. 측정은 각 방사선 사진의 임플란트 덮개나사 최상방에서 변연골까지의 거리를 측정하여 골 형성량을 계산하였다. 수술 직후와 수술 8주 후에 임플란트 안정도 (Implant Stability Quotient value; ISQ value)를 측정하였다. 통계분석을 위해 SPSS software를 사용하여 Man-Whitney ranksum test와 Wilcoxon signed ranksum test를 시행하였다. 통계적 유의수준은P=.05를 기준으로 하였다. 결과: 골형성단백질이 코팅된 임플란트에서 수직 결손부 상방으로 약 0.6 mm의 골 형성이 관찰되었다. 대조군에서는 제한된 양의 골 형성 혹은 골 소실이 일어났다. 각 시기에 따른 실험군과 대조군간의 골 형성량에 유의한 차이가 있었다 (P<.05). ISQ value는 수술 직후에는 실험군과 대조군의 유의한 차이가 없었지만 수술 8주 후에는 실험군에서 대조군 보다 유의하게 높게 증가되었다 (P<.05). 결론: 골형성단백질이 코팅된 임플란트는 완전히 치유된 치조골에서 임상적으로 유의한 골 증대 효과가 있는 것으로 보인다.